Avocado trees can suffer from a number of problems, including lack of fruiting, insects and diseases. If caught early, many diseases and insect infestations are easy to fix. In some cases, insect infestations may only affect the avocado skins without harming the insides of the fruit. How you deal with the problem will depend on what is causing it and how it is manifesting.
If your avocado tree is not flowering and producing fruit, this may be because you grew the tree from seed. Trees grown from avocado pits generally will not flower and fruit. To produce fruit on the tree, graft a scion, or cutting, from an existing fruiting tree to a non-fruiting rootstock.
During hot, dry weather and due to lack of water, or salty soil, avocado trees can suffer from tip burn. When you experience a hot period with little precipitation, watering your avocado trees regularly can help prevent this problem. Check the top ¼ inch of soil. If it feels dry, give your tree 2 to 4 inches of water.
In some cases, your tree may drop all of its leaves when it flowers. These leaves should immediately start to grow back and are not a reason to worry.
One of the most serious problems with avocado trees is anthracnose, a disease that occurs as the avocados reach maturity. This disease first appears as small brown spots that can expand to around half an inch and cause the avocados to split. Fungicides may help when first noticing the brown spots.
Avocado trees are susceptible to a number of different insect pests. Avocado thrips lay eggs on the underside of the tree's leaves and inside the fruit. Although thrips do not tend to harm the tree, the larvae will feed on immature fruit. Although the quality of the internal fruit is not affected, thrips cause surface scarring. Apply insecticides to control thrips.
Avocado lace bugs primarily occur in the Caribbean, Mexico and Southeastern United States. Avocado lace bugs damage leaves and can leave your tree damaged to the point that it will drop all of its leaves. If you have a tree infested with avocado lace bugs, be careful not to transfer infected material near other avocado trees. Treat an avocado lace bug infestation with insecticides.